The US has formally withdrawn from the Intermediate-range Nuclear Force (INF) Treaty. The Treaty was signed by President Reagan of the US and President Gorbachev of the Union of Soviet Socialist Republics (USSR), now Russia in 1987. It was the first treaty to eliminate an entire class of nuclear weapons, those with missiles that could fly between 500 and 5,500 kilometers. The purpose of the treaty was quite explicit: to prevent an outbreak of nuclear war between the US and the USSR on the European continent. Intercontinental ballistics missiles remained, but their number was limited by another treaty, the Strategic Arms Reduction Treaty (START, which expires in 2021. The US withdrew for a number of reasons. First, it claimed that Russia had violated the treaty by developing an intermediate-range missile. The Russians have not tested the missile beyond the proscribed distance limits, but the new missile is mobile, so the issue of testing is moot. Second, the US worries about Chinese development of an intermediate-range missile and wants to rewrite the treaty to include China. The Chinese have not indicated any interest whatsoever in signing such a pact.